In a letter to acting IRS Commissioner Daniel Werfel on Tuesday, Grassley said it violates an April directive from the White House to agencies to halt all bonuses because of budget constraints. Werfel, who worked at the Office of Management and Budget at the time, was the author of those guidelines.

“The IRS always claims to be short on resources,” Grassley said in a statement on Wednesday. “But it appears to have $70 million for union bonuses.”